The objective of this study is to determine if DNA bending induced by binding of the human ER plays a role in transcription activation of E- responsive genes. Aim l is to determine if the effectiveness of ER in DNA bending is influenced by E, salt activation, or phosphorylation. Aim 2 is to determine if unoccupied ER, ER occupied by E, and ER occupied by antiE bend DNA in the same direction. Aim 3 is to determine if the extent of DNA bending induced by the ER correlates with the magnitude of gene transcription activation by the ER.